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When Benzene diazonium Chloride is treated with CuBr and HBr, then Sandmeyer reaction takes place and Bromo benzene is obtained as the product.

In case if you don't what is Sandmeyer reaction then I would like to tell you that it is a reaction in which synthesis of aryl halides takes place from aryl diazonium salts using copper salts as reagents or catalysts.

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